Hi
I have two generated png images.
First one has 850x850 size and 72dpi
second one is a little bit smaller: 847x847 and also 72dpi
When I import first one to lighburn, it gets the desired size - almost 300mmx300mm, but importing second one, it gets 423.5mmx423.5mm
Both images are generated with the same method, I only change the desired size to get a little bit less than 300x300 for my laser.
Could you please check what i wrong?
And by the way, I have a question related to my images. To get the best final result, should I set the final image resolution to 254dpi to achieve exactly one line of pixels to one laser line? Or there is some other setting where increasing dpi factor does not make sense?
Thanks in advance
I get completely different results on my system (Win 10), LB 1.4.03. When imported into LB the 850x850 image comes in at 224.868mm sq. and the 847x847 image comes in at 224.074 sq. In my case this would suggest that LB is assuming 96 DPI rather than the 72 DPI specified in the image files. I’ve checked settings and I’ve not found anything which might account for the discrepancy. Very strange that we should get different results!
EDIT:
Ok, after further testing I think it might be a problem with the generator software. I opened your 850x850 image in Affinity Photo and resized it to 850x850 96 DPI. This imported to LB as 224.868mm sq. I then resized in Affinity to 1134x1134 96 DPI and this came into LB as 300mm sq. Looking at the tags in the image files it appears that the DPI tag is missing in your original files but is present in the resized files exported from Affinity. LB appears to read the DPI tags correctly but if they’re missing it assumes 96 DPI.
I have read several topics and there was always an information, that for png images, LB reads dpi from a file itself. And for most cases, it corresponds with my observations as I create png images for the desired final size in mm. If you or someone else in the future would like to test, I can create a similar image with any size/dpi.
yes, this one is imported with correct size, but I think it might be a coincidence here (or not?)
For my both images, I can see the 72x72 Resolution information in system (macos), it is also visible in online tools that I used, but your image seems to not having any dpi information, so maybe LB assumes 72 as a lucky guess. What do you think?
And still, I am generating both images in the same way, it looks like this one image revealed some LB issue
That’s very odd, I have found the exact opposite! I checked the properties of your files and mine with XnView MP. Here’s what I see for my 847x847 72 DPI file:
could you please check once again? The file name for my image is 847x847.png, but it shows 850x850 size. And the print size seems to be correct here.
Please make sure that you are checking my original 847 size file and let me know what you can see in the metadata
But I am sure LB is reading my metadata, let me show you.
I am attaching an image with desired size 50x50mm with 254dpi. It loads to LB at exactly desired size.
As you can see, when I import it into LB I get 132.275 x 132.275mm (equivalent to 500px x 500px @96 DPI), so as before: different to what you’re seeing on your Mac.
And as before I’m not seeing any DPI specified in the metadata for this file either.
Ok, I’ve just had a thought… it’s possible that the forum is stripping metadata from the files we’re uploading. Could you add a .TXT file extension and upload again?
I guess you are right. If I upload txt. it still seems to be recognized as png, but I downloaded my own image from this thread and the dpi information is lost. You can actually do the same with yours.
So, I will try to somehow expose my initial files and define my problem once again
